Balancing Chemical Equations (Lesson)

Introduction to Balancing Equations

● Balancing equations is essential in chemistry.
● It ensures the law of conservation of mass is

followed.
○ Matter is neither created nor destroyed

Understanding Reactants and Products

● Reactants are substances that start a chemical

reaction.

● Products are what you get after the reaction.

● Can you identify the reactants and products in this

equation: H₂ + O₂→ H₂O?

Coefficients - Big numbers that go in front of the molecule, tell us how many molecules there are in a set

Subscript - Little numbers that hang off the Atom. Tells us how many of each type of atom are in the set.

Steps to Balance Equations

● Step 1: Take Inventory
● Step 2: Is it balanced?
● Step 3: Change Coefficients to balance

equation

Simple Example: H₂ + O₂ → H₂O

● Start with:

____H₂ + ____O₂→ ____H₂O

● Count:
● Adjust:

Example: Fe + O₂ → Fe₂O₃

●Start with
Count:
● Adjust:

Example: C₃H₈ + O₂ → CO₂ + H₂O

● Start with:
● Count:
● Adjust: